Water-insoluble azomethine compounds

ABSTRACT

Condensing of 1-formyl-2-hydroxy-3-naphthalenecarboxylic acid arylamides with ammonia or aromatic amines yields novel azamethines which are useful as coloring matters, especially as pigments.

This application is a continuation of copending application Ser. No. 653,119, filed Jan. 28, 1976, now abandoned, which application was a continuation-in-part of copending application Ser. No. 550,918, filed Feb. 19, 1975, now abandoned.

The present invention relates to new water-insoluble azamethine compounds of the general formula I ##STR1## in which A stands for hydrogen, a radical of the benzene or naphthalene series or a heterocyclic radical, Ar stands for the naphthyl group or the phenyl group which groups may carry one to three substituents selected from the group consisting of lower alkyl, lower alkoxy, lower alkylsulfonyl, carboxy, lower carbalkoxy, trifluoromethyl, nitro, cyano, lower alkanoylamino, benzoylamino, carbonamido or sulfonamido groups and/or halogen atoms, preferably chlorine or bromine atoms; or for a benzimidazolene, chlorobenzimidazolone, tetrahydrodioxoquinazolone, tetrahydrodioxoquinoxaline, phthalimide or tetradydrodioxophthalazine radical, which heterocyclic groups may be further substituted, and X stands for a hydrogen, chlorine or bromine atom.

By "lower" there are to be understood groups being or containing alkyl groups of 1 to 4 carbon atoms.

This invention moreover relates to a process for the preparation of these compounds of formula I or mixtures thereof, which comprises condensing 1 mol of one or more aldehydes of the general formula II ##STR2## in which Ar and X are defined as above, with 1 mol of one or more amines of the general formula III

    a -- nh.sub.2                                              (iii)

in which A is defined as above.

As radicals Ar, there are mentioned, for example, phenyl, o-, m-, p-tolyl, o-, m-, p-methoxyphenyl, o-, m-, p-ethoxyphenyl, o-, m-, p-chlorophenyl, o-, m-, p-bromophenyl, o-, m-, p-nitrophenyl, 2,4-dimethylphenyl, 2,5-dimethoxyphenyl, 2,4-dichlorophenyl, 2,5-dichlorophenyl, 2,4,5-trichlorophenyl, 2-chloro-3-methylphenyl, 2-chloro-4-methylphenyl, 2-chloro-5-methylphenyl, 3-chloro-2methylphenyl, 4-chloro-2-methylphenyl, 2-methoxy-5-chlorophenyl, 2,5-dimethoxy-4-chlorophenyl, 2,4-dimethoxy-5-chlorophenyl, 2-methoxy-4-chloro-5-methylphenyl, 4-acetylaminophenyl, 4-benzoylaminophenyl, benzimidazolyl, phthalimidyl, tetrahydrodioxoquinoxalyl, tetrahydrodioxoquinazolyl or tetrahydrodioxophthalazinyl.

Preferred azamethine compounds are particularly those corresponding to the general formula IV ##STR3## in which X and Ar are defined as above, and Y₁,Y₂ and Y₃ may be identical or different and stand for hydrogen or non ionic substituents.

As non ionic substituents, there are mentioned, for example, halogen atoms, especially chlorine or bromine atoms; alkyl groups, especially alkyl groups of 1 to 4 carbon atoms, preferably methyl or ethyl groups; alkoxy groups, especially having 1 to 4 carbon atoms, preferably methoxy and ethoxy groups; nitro groups; alkyl- or arylsulfonyl groups, especially alkylsulfonyl groups having 1 to 4carbon atoms in the alkyl moiety, phenyl, tolyl, sulfonamido-phenyl, carbon-amidophenyl-sulfonyl, or the N-methyl- or N-ethyl-substituted radicals thereof, carboxylic acid ester groups, optionally substituted sulfonic acid amide or carboxylic acid amide groups, or acylamino groups. Among the carboxylic acid esters groups, the carboxylic acid alkyl ester groups having 1 to 4 carbon atoms in the alkyl moiety are preferred, among optionally substituted sulfonic acid amide or carboxylic acid amide groups, those groups which carry one or two lower alkyl groups or a phenyl group which may again be substituted by non-ionic substituents, such as lower alkyl, lower alkoxy, carbonamide or sulfonamide groups and/or chlorine atoms, are preferred.

Acylamino groups are, in particular, lower alkanoylamino groups, such as acetyl- or propionylamino groups, and benzoyl or phenylsulfonylamino groups which carry one or more of the above-cited non ionic substituents, among them preferably a radical of the formula ##STR4## in which R stands for hydrogen, lower alkyl, lower alkoxy, a sulfonamide or carbonamide group or a chlorine atom.

Especially valuable properties are found in the new azamethine compounds, wherein at least one of the substituents Y₁, Y₂ or Y₃ contains a grouping of the formula --CO--NH-- or wherein Y₁ and Y₂, taken together, stand for a grouping of the formula --NH--CO--NH--, --CO--NH--CO--, --NH--CO--NH--CO--, --NH--CO--CO--NH-- or --CO--NH--NH--CO--.

As aromatic amines of formula III, there are especially mentioned amino-benzamides, amino-benzanilides, acylaminoanilines, amino-phenyl-sulfonamides, alkyl- or arylsulfonaminoanilines, amino-benzimidazoles, amino-benzoxazoles, amino-benzthiazoles, amino-phthalic acid imides, amino-quinazolinones, amino-quinoxalines, or amino-phthalazines, which are known and are generally prepared by reduction of the corresponding nitro compounds.

The 1-aldehydes of 2-hydroxy-naphthalene-3-carboxylic acid arylides of formula II, used as starting compounds, are obtained by reacting 2-hydroxy-naphthalene-3-carboxylic acid arylides with hexamethylene tetramine in the presence of a lower aliphatic carboxylic acid with a mineral acid.

The condensation of one mol of an aldehyde of formula II with one mol of an amine of formula III may be carried out both in a neutral and acid, optionally aqueous medium, or in an organic solvent, such as an alcohol, for example methanol, ethanol or butanol, in an aliphatic carboxylic acid, for example acetic acid, in dimethylformamide, xylene, chlorobenzene, dichlorobenzene or nitrobenzene. It generally proceeds rapidly with quantitative yield at a temperature of 50 to 100° C; advantageously there may be used a solvent or a mixture of solvents at an elevated temperature, for example from 130 to 170° C or more, while water set free by the condensation reaction is separated by azeotropic distillation. In some cases, it may be advantageous to use the amines in the form of their salts with mineral acids and to carry out the reaction by adding an at least equivalent amount of ammonia, an ammonium salt or an aliphatic, aromatic or heterocyclic amine, for example triethylamine, N,N-dimethylaniline or pyridine.

The condensation reaction may advantageously be carried out in the presence of surface-active compounds or resin soaps or by adding these additives during or after the isolation of the dyestuffs, whereupon the dispersibility, the degree of glazing and/or the particle size distribution, which is responsible for a good gloss of the dyeings, are positively influenced.

For obtaining optimum coloristic properties, it may sometimes be advantageous to convert the final pigment into a finely divided form by heating the pigment in a solvent, optionally in the presence of water or salt solutions.

As solvents suitable for this purpose, there are mentioned those in which the dyestuffs are insoluble but promote a certain degree of superficial dissolving under the finishing conditions, for example aliphatic alcohols, such as ethanol, isopropanol, iso- or n-butanol; chlorinated aromatic solvents, such as chlorobenzene and chlorotoluene or dichlorobenzenes, as well as aprotic polar solvents, for example dimethylformamide, dimethylacetamide, dimethylsulfoxide, polyalkyl ureas and phosphoric acid amides.

In some cases, a fine division may also be brought about by grinding the pigments with salts or in solvents; the dry grinding operation being preferably performed in vibrating mills with a subsequent separation of the salt by dissolution in water, optionally followed by a wet grinding operation or a high-temperature treatment with solvents.

As salts, there are generally used the alkali metal or alkaline earth metal salts or halohydric acids or of sulfuric acid, for example sodium or potassium chloride and sodium or magnesium sulfate.

The solvents used for the wet grinding operation are generally the same as mentioned above, for example alcohols, acid amides or dimethylsulfoxide.

The new compounds are valuable dyeing agents, especially valuable pigments suitable in particular for printing pastes and inks. They may, however, also be used for being incorporated into high-molecular-weight organic materials, for example cellulose ethers and esters, such as acetyl cellulose or nitro-cellulose, polyamides, polyurethanes or polyesters, natural or synthetic resins, for example aminoplasts, especially in urea- and melamine-formaldehyde resins, alkyd resins, phenoplasts, polycarbonates, poly-olefins, such as polyethylene or polypropylene, polyvinyl chloride, polyacrylonitrile, polyacrylic acid esters, rubber, casein, silicone and silicone resins, as such or in mixture with one another. For such an incorporation, it does not matter whether the above-cited high-molecular-weight compounds are available as plastic masses, melts or spinning solutions, lacquers or printing pastes and inks. Depending on the intended purpose, it proved to be useful to incorporate the new pigments as toners or in the form of compositions.

The new pigments are distinguished by clear shades, high fastness to light, high tinctorial strength, high transparency as well as an excellent stability on storage and rheological properties in printing varnishes.

They are therefore excellently suitable for use in multicolor paper printing. Owing to their good fastness to solvents and migration, the pigments of the invention are advantageous also for the coloration of lacquers and plastic materials.

The following Examples illustrate the invention.

EXAMPLE 1

14.6 Grams of 2-hydroxynaphthalene-3 -carboxylic acid anilide 1-aldehyde were heated at the boil in a mixture of 200 ml of ethanol and 200 ml of glacial acetic acid. Then a solution of 10.8 g of 3-amino-4-chloro-6-methyl-acetanilide in 100 ml of glacial acetic acid were added to the above solution, whereupon an intensely yellow-colored product precipitated within a short time. Stirring was continued for 1 hour at 95° C, the mixture was cooled and suction-filtered at room temperature. After washing with a small amount of methanol and water, 20.9 g of a yellow pigment of the formula ##STR5## were obtained.

EXAMPLE 2

29.2 Grams of 2-hydroxy-naphthalene-3-carboxylic acid anilide 1-aldehyde were dissolved at 75° C in 200 ml of dimethylformamide. At this temperature, a solution of 28.5 g of 3-amino-4-methoxy-benzoyl-amino-4'-benzamide in 100 ml of dimethylformamide, 50 ml of glacial acetic acid and 50 ml of water was added dropwise. Stirring was continued for 3 hours at 100° C, the product was suction-filtered, washed with water and dried. 46.4 Grams of a reddish yellow pigment of the formula ##STR6## were obtained.

EXAMPLE 3

7.3 Grams of 2-hydroxy naphthalene-3-carboxylic acid anilide 1-aldehyde were dissolved at the boil in 300 ml of ethanol. A solution of 4.4 g of 5-aminobenzimidazolone in 100 ml of glacial acetic acid was added at 80° C, whereupon an intensely orange red colored pigment precipitated at once. Stirring was continued for 1 hour at 80° C, the mixture was allowed to cool to 20° C, suction-filtered, washed with methanol and water and dried.

Yield: 10 g of a pigment of the formula ##STR7##

EXAMPLE 4

19.3 Grams of 2-hydroxy naphthalene-3-carboxylic acid-2',5'-dimethoxy-4'-chloroanilide 1-aldehyde were mixed in a high-speed stirrer with 200 ml of water and 100 ml of glacial acetic acid. While stirring, a solution of 12.5 g of 3-amino-4-methoxy-benz-anilide in 100 ml of dimethylformamide was added to this suspension. The temperature was maintained at 95° C for 10 hours, the product was then suction-filtered, washed with hot water and dried.

Yield: 23.7 g of a reddish yellow pigment of the formula ##STR8##

Upon incorporation into polyvinyl chloride the pigment thus obtained yielded a reddish yellow coloration having a very good purity, color intensity and fastness to migration and light.

EXAMPLE 5

38.6 Grams of 2-hydroxy naphthalene-3-carboxylic acid-2',5'-dimethoxy-4'-chloroanilide 1-aldehyde were dissolved at 120° C in 500 ml of dimethylformamide. Then, a solution of 19 g of 2-amino-4-acetylamino-anisole in 100 ml of water and 50 ml of glacial acetic acid were added dropwise. Stirring was continued for 3 hours at 100° C, the mixture was suction-filtered when cooled to room temperature, washed with water and dried.

Yield: 42.2 g of a reddish yellow pigment of the formula ##STR9##

EXAMPLE 6

29.2 Grams of 2-hydroxy-naphthalene-3-carboxylic acid anilide 1-aldehyde were heated at the boil in 500 ml of glacial acetic acid and 500 ml of ethanol. To the hot suspension, a solution of 14 g of anthranilic acid in 50 ml of dimethylformamide was added, whereupon a clear solution was obtained, from which at once a reddish yellow pigment crystallized. The product was refluxed for 5 hours, cooled and suction-filtered at room temperature. It was washed with methanol and water and dried.

Yield: 38.5 g of a pigment of the formula ##STR10##

EXAMPLE 7

7.7 Grams of 2-hydroxy naphthalene-3-carboxylic acid-2'-methylanilide-1-aldehyde were dissolved at 80° C in 1000 ml of ethanol, and a solution of 4.6 g of 5-aminobenzimidazolone in 100 ml of glacial acetic acid was added thereto. The mixture was then refluxed for 2 hours. The orange-colored pigment was suction-filtered, washed with hot ethanol and water and dried.

Yield: 9.9 g of a pigment of the formula ##STR11##

EXAMPLE 8

A solution of 31.4 g of 5-amino-2-benzoylamino-1,4-dimethoxybenzene in 200 ml of glacial acetic acid, 400 ml of water and 10 ml of a 10% solution of oxethylated stearyl alcohol was prepared. While stirring rapidly, a solution of 30.5 g of 2-hydroxy-3-carboxylic acid-2'-methylanilide-1-aldehyde is in 200 ml of dimethylformamide was added dropwise. Stirring was continued for 3 hours at 100° C, the reaction mixture was cooled and the product suction-filtered at room temperature. After washing with methanol and water and subsequent drying, 52.5 g of an intensely yellow colored pigment of the formula ##STR12## were obtained.

EXAMPLE 9

32.1 Grams of 2-hydroxy-3-carboxylic acid-2'-methoxy anilide 1-aldehyde were dissolved at 80° C in 300 ml of glacial acetic acid. This solution was combined with 10 ml of a 10% aqueous solution of oxethylated stearyl alcohol, and 27.7 g of 5-amino-2-benzoylamino-3-methyl-6-methoxy-benzene in 200 ml of glacial acetic acid and 300 ml of water were added. Stirring was continued for 3 hours at 100° C and, after the usual workup, 50.1 g of an intensely orange colored pigment of the formula ##STR13## were obtained.

EXAMPLE 10

33.5 Grams of 2-hydroxy-3-carboxylic acid-2'-ethoxyanilide-1-aldehyde were dissolved at 70° C in 250 ml of dimethylformamide. This solution was added dropwise within 20 minutes to a solution of 31.4 g of 5-amino-2-benzoylamino-1,4-dimethoxybenzene in 200 ml of glacial acetic acid, 300 ml of water and 10 ml of a 10% aqueous solution of an oxethylated stearyl alcohol. The mixture was heated to 95° C and this temperature was maintained for 3 hours, the product was suction-filtered while hot, washed with hot water and dried. Yield: 51.2 g of a red azamethine pigment of the formula ##STR14## were obtained.

EXAMPLE 11

33.2 Grams of 2-hydroxy naphthalene-3-carboxylic acid-4'-acetylamino-anilide-1-aldehyde were heated at the boil in 350 ml of ethanol. Then 4 g of a concentrated aqueous ammonia solution in 30 ml of ethanol were added dropwise. Refluxing was continued for 60 minutes and, after the usual work-up, 32.7 g of a reddish yellow azamethine pigment of the formula ##STR15## were obtained.

EXAMPLES 12 - 26

The following Table comprises further dyestuffs of the invention which can be prepared from amines of the formula III (A--NH₂) and 1-naphthaldehydes of the above formula II, according to the method disclosed in Examples 1 to 11:

                                      TABLE                                        __________________________________________________________________________                                                    shade pro-                                                                     duced with                                                1-naphthaldehyde(II) azamethine                      Example                                                                             ANH.sub.2            Ar                 X pigment                         __________________________________________________________________________     12   NH.sub.3                                                                                             ##STR16##         Br                                                                               yellow                          13                                                                                   ##STR17##                                                                                           ##STR18##         H reddish yellow                  14                                                                                   ##STR19##                                                                                           ##STR20##         H red                             15                                                                                   ##STR21##                                                                                           ##STR22##         H yellowish red                   16                                                                                   ##STR23##                                                                                           ##STR24##         H reddish yellow                  17                                                                                   ##STR25##                                                                                           ##STR26##         H yellowish red                   18                                                                                   ##STR27##                                                                                           ##STR28##         H yellowish red                   19                                                                                   ##STR29##                                                                                           ##STR30##         H yellowish red                   20                                                                                   ##STR31##                                                                                           ##STR32##         H orange                          21                                                                                   ##STR33##                                                                                           ##STR34##         H yellowish red                   22                                                                                   ##STR35##                                                                                           ##STR36##         H red                             23                                                                                   ##STR37##                                                                                           ##STR38##         H yellow                          24                                                                                   ##STR39##                                                                                           ##STR40##         Br                                                                               reddish yellow                  25                                                                                   ##STR41##                                                                                           ##STR42##         H yellowish orange                26                                                                                   ##STR43##                                                                                           ##STR44##         H yellowish red                   __________________________________________________________________________

                                      TABLE                                        __________________________________________________________________________                                1-naphthaldehyde (II)                               Example                                                                             ANH.sub.2             Ar            X shade                               __________________________________________________________________________     27                                                                                   ##STR45##                                                                                            ##STR46##    H yellowish orange                    28   "                                                                                                     ##STR47##    H yellowish orange                    29   "                                                                                                     ##STR48##    H orange                              30                                                                                   ##STR49##                                                                                            ##STR50##    H yellowish red                       31   "                                                                                                     ##STR51##    H yellowish red                       32                                                                                   ##STR52##                                                                                            ##STR53##    H reddish orange                      33                                                                                   ##STR54##                                                                                            ##STR55##    H yellowish red                       34                                                                                   ##STR56##                                                                                            ##STR57##    H yellow                              35                                                                                   ##STR58##                                                                                            ##STR59##    H yellowish red                       36                                                                                   ##STR60##                                                                                            ##STR61##    H yellowish orange                    37                                                                                   ##STR62##                                                                                            ##STR63##    H yellowish red                       38                                                                                   ##STR64##                                                                                            ##STR65##    H yellowish red                       39                                                                                   ##STR66##                                                                                            ##STR67##    H yellowish orange                    __________________________________________________________________________

EXAMPLE 40

0.8 Gram of the pigment obtained according to Example 1, 2.4 g of alumina hydrate and 4.8 g of a letter printing varnish were mixed on a three-roller mill, and the mixture was triturated to yield a letter printing ink having a pigment content of 10% and producing yellow prints of high purity and color intensity.

Upon incorporation with a lacquer or a spinning solution, yellow colorations of good fastness to light and solvents were obtained.

EXAMPLE 41

67 Grams of polyvinyl chloride, 33 g of a platicizer composition consisting of a mixture of equal parts of dioctyl phthalate and dibutyl phthalate, 0.1 g of the pigment obtained according to Example 3, and 0.5 g of titanium dioxide were mixed for 15 minutes at 150° C in a roller mill to produce a foil with an orange-red coloration, which was distinguished by a high intensity, pure shade and good fastness to light and migration.

EXAMPLE 42

4.5 Grams of the pigment obtained according to Example 5 were shaken for 45 minutes in a vibration ball mill with 25.5 g of a lacquer consisting of a 20% solution of alkyd resin in xylene, then 60 g of a clear varnish consisting of 52.5 parts by weight of a 70% alkyd resin solution in xylene, 35 parts by weight of a 55% melamine resin solution in butanol, 2.5 parts by weight of butyl glycol, 5 parts by weight of butanol and 5 parts by weight of white spirit were added.

A reddish yellow colored full shade lacquer was obtained, it was sprayed onto an aluminum sheet and stoved for 30 minutes at 140° C. The reddish yellow coloration thus obtained had a satisfactory fastness to overlacquering and a good fastness to light and weathering.

EXAMPLE 43

0.8 Gram of the pigment obtained according to Example 7 were processed as in Example 27 to yield a letter printing ink which provided clear orange-colored prints of high color intensity and good fastness to light. 

I claim:
 1. A compound of the formula ##STR68## wherein X is hydrogen, chlorine or bromine, Ar is phenyl or naphthyl which are unsubstituted or substituted by 1 to 3 substituents selected from the group consisting of halogen; lower alkyl; lower alkoxy; trifluoromethyl; nitro; cyano; carboxy; lower carbo-alkoxy; lower alkyl sulfonyl; carbamoyl; sulfamoyl; carboxylic or sulfonic acid mono- or di-(lower alkyl)amide; carboxylic or sulfonic acid anilide which are unsubstituted in the phenyl nucleus or substituted by halogen, lower alkyl, lower alkoxy, cyano, carbamoyl or sulfamoyl; lower alkanoyl amino; phenyl sulfonyl or benzoyl amino which are unsubstituted in the phenyl nucleus or substituted by halogen, lower alkyl, lower alkoxy, cyano or nitro; or two substituents on Ar being phenyl together stand for a fused saturated 5- or 6-membered ring consisting of two adjacent carbon atoms of the phenyl nucleus and further ring members selected from the group consisting of --CO--, --NH--, --O-- and --S--; and A is benzimidazolonyl-(2) which is unsubstituted or substituted by chlorine, methyl, methoxy, ethoxy, or nitro.
 2. A compound as defined in claim 1, wherein Ar is naphthyl; phenyl; phenyl substituted by 1 to 3 substituents selected from the group consisting of chlorine, bromine, lower alkyl, lower alkoxy, trifluoromethyl, carboxy, nitro, lower carboalkoxy, lower alkanoylamino, benzoylamino, carbamoyl, sulfamoyl, carboxylic or sulfonic acid mono- or di-(lower alkyl)-amide, and carboxylic or sulfonic acid anilide which are unsubstituted or substituted in the phenyl nucleus by lower alkyl, lower alkoxy, chlorine or carbamoyl; phthalimidyl, benzimidazolonyl, benzoxazolonyl, tetrahydrodioxoquinazolonyl, tetrahydrodioxoquinoxazolyl or tetrahydrodioxophthalazinyl; which heterocyclic radicals are unsubstituted or substituted in the benzo nucleus by chlorine, bromine, lower alkyl, lower alkoxy or nitro.
 3. A compound as defined in claim 1, wherein X is hydrogen and Ar is phenyl substituted by 1 to 3 substituents selected from the group consisting of chlorine, methyl, methoxy and ethoxy.
 4. A compound as defined in claim 1, wherein X is hydrogen and Ar is phenyl, chlorophenyl, dichlorophenyl, tolyl, anisyl, ethoxyphenyl or dimethoxy chlorophenyl.
 5. A compound of the formula ##STR69## wherein X is hydrogen, Ar is phenyl, chlorophenyl, dichlorophenyl, tolyl, anisyl, ethoxyphenyl or dimethoxy chlorophenyl; and A is benzimidazolonyl-(2) which is unsubstituted or substituted by chlorine, methyl, methoxy, ethoxy, or nitro.
 6. The compound as defined in claim 5, wherein A is 6-nitrobenzimidazol-2-on-5-yl and Ar is p-chlorophenyl.
 7. The compound as defined in claim 5, wherein A is benzimidazol-2-on-5- yl and Ar is o-chlorophenyl.
 8. The compound as defined in claim 5, wherein A is 6-chlorobenzimidazol-2-on-5-yl and Ar is 2,5-dichlorophenyl.
 9. The compound as defined in claim 5, wherein A is 6-ethoxybenzimidazol-2-on-5-yl and Ar is 2,5-dichlorophenyl.
 10. The compound as defined in claim 5, wherein A is benzimidazol-2-on-5-yl and Ar is o-toluidino. 